Detachable joint between continuous-casting starter bar and casting

ABSTRACT

Described is a starter bar having a detachable head which when attached to the bottom of a continuous-casting may be detached from the starter bar by lateral deflection of the leading end of the casting relative to the starter bar. The detachable head consists of a cup-shaped chill plate slidably disposed in a recess in the head end of the starter bar. A key is fixedly attached to the bottom of the chill plate with its upper end projecting upwardly and its lower end depending downwardly from the chill plate bottom into a slot extending transversely of the head portion of the starter bar. The upper portion of the key serves as an anchor for the lower end of a continuously formed casting as it solidifies. In practice, the leading end of a descending continuous-casting supported by a starter bar is deflected by a bending roll which deflection causes the key and attached chill plate to slide laterally out of the recess and slot, respectively, of the starter bar head to thus effect separation of the starter bar from the casting.

m Unite States atet [151 3,643,731 Stull Feb. 22 1972 [54] DETACHABLEJOINT BETWEEN CONTINUOUS-CASTING STARTER BAR Primary Examiner-J. SpencerOverholser A CASTING Assistant Examiner-John E. Roethel Attorney-DonaldS. Ferito [72] Inventor: James T. Stull, Jackson Township, ButlerCounty, Pa. [57] ABSTRACT [73] Assignee: United States Steel CorporationDescribed is a starter bar having a detachable head which when attachedto the bottom of a continuous-casting may be [22] May 1969 detached fromthe starter bar by lateral deflection of the lead- [2l] Appl. No.:828,161 ing end of the casting relative to the starter bar. Thedetachable head consists of a cup-shaped chill plate slidably disposed Vv in a recess in the head end of the starter bar. A key is fixedly lllattached to the bottom of the chi" plate with its upper end 58] d164/274 projecting upwardly and its lower end depending downwardly o arcfrom the chill plate bottom into a slot extendin transversely 8 56]References Cited of the head portion of the starter bar. The upperportion of the a key serves as an anchor for the lower end of acontinuously UNITED STATES PATENTS formed casting as it solidifies. Inpractice, the leading end of a descending continuous-casting supportedby a starter bar IS 3,080,625 3/ 1963 Pearson et al. ..l64/274 d fl t dby a bending to which d fl ti causes the key 3,239,894 3/ 1966 Master?et 164/274 and attached chill plate to slide laterally out of the recessand 336L161 7/ Andflelak e "164/274 slot, respectively, of the starterbar head to thus effect separai g ll lf ct tion of the starter bar fromthe casting. a uccl 3,525,381 8/ 1970 Leese et al. 164/274 X 2 Claims, 6Drawing Figures DETACI-IABLE JOINT BETWEEN CONTINUOUS- CASTING STARTERBAR AND CASTING BACKGROUND OF THE INVENTION The present inventionrelates generally to continuous-casting and, more particularly, to astarter bar for continuous-casting having a detachable joint in its headportion adapted to be attached to a continuous-casting.

It is customary in continuous-casting to fit the head end of a starterbar snugly in the lower end of the tubular flow-through chill mold ofthe caster to temporarily close the bottom of the mold. The starter bar,in addition to closing the discharge end of the chill mold while moltenmetal is first being poured thereinto, also serves to initiate downwardtravel of the metal column or casting formed in the mold and support itas it descends from the mold through guide rolls and pinch rolls locatedbelow the mold. The starter bar was severed from the casting after thebar had passed through the pinch rolls.

Prior to my invention the starter bar was severed from the casting bytorch-cutting the casting a short distance above the top of the starterbar. The starter bar, with a short length of casting attached to the topthereof, was then lowered vertically independently of the casting. Atthe bottom of its vertical travel, the starter bar was lowered to ahorizontal position and transported away. The short length of castingwhich remained attached to the starter bar was then removed so that thestarter bar could be used again at the beginning of a subsequent castingoperation. Meanwhile, after severance from the starter bar, the castingwas deflected from its vertical pathby means of a bending roll and wasguided in a curved path from a vertical direction of travel to ahorizontal one by means of rolls mounted in a guide frame or rack.

Cutting the casting to separate the starter bar as above described hadcertain disadvantages inherent therein. For example, it was necessary toremove the short length of casting which remained attached to thestarter bar after cutting before the starter bar could be reused. Thishad to be done manually and usually required considerable time andlabor. Another disadvantage was the fact that the cutting torchesconventionally used to cut away the lower part of the casting and thestarter bar attached thereto required an excessively long time to makethe cut. Such factors adversely affected production from the continuouscaster.

Prior to my invention, in efforts to eliminate the foregoingdisadvantages, various devices were tried whereby an expendabledetachable head portion was provided to connect the head end of thestarter bar with the bottom of the casting. With this type ofarrangement, the starter bar was disconnected from the detachable headafter the casting had descended through the pinch rolls. Detachableheads of this type of which I am aware proved unsatisfactory inasmuch asmolten metal from the continuous-casting leaked into the joint betweenthe detachable head and the starter bar and froze the two together sothat separation could not be accomplished in the manner intended.

SUMMARY OF THE INVENTION The present invention proposes to provide adetachable head adapted to fit detachably in a recess in the headportion of the starter bar. The detachable head includes a chill platewhich is fitted slidably into the recess of the head portion of thestarter bar, and a key, preferably in the form of a rail section. Therail section key is fixedly attached, as by welding or the like, to thebottom of the chill plate with the upper portion of the web of the railsection projecting upwardly from the bottom of the chill plate and thelower portion of the rail section web depending downwardly from thechill plate into an inverted T-slot which communicates with the recessin the head of the starter bar. The weld attaching the rail section tothe bottom of the chill plate is made around the web where it passesthrough the plate bottom. Thus, this weld also serves to seal theopening in the chill plate bottom and prevent molten metal from leakinginto the recess or the slot therebelow. The

head of the inverted T-slot is proportioned to slidably accommodate thebase of the rail section key. The chill plate is complementary in theshape to the recess in the starter bar head and is provided with acircumferential outwardly projecting lip around the top thereof whichrests on the top of the starter bar head to support the chill plate.This lip also prevents leakage of molten metal into the recess under thechill plate. A packing of heat-resistant material such as asbestossurrounds the outwardly projecting lip of the chill plate so as toprovide a seal between the starter bar head and the inner walls of thecasting mold when the starter bar is inserted in the bottom thereof.Adjacent ends of the recess and slot in the head por tion of the starterbar are open and communicate with each other so that after initiallypoured molten metal enters the cup-shaped chill plate and solidifiesaround the head portion of the rail section key, the rail section keyand chill plate are laterally disconnected from the starter bar when theleading end of the casting is laterally deflected by the bending roll.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a vertical sectional view,partly in section, with parts broken away for clarity, showing thestarter bar of my in vention inserted in the bottom of acontinuous-casting mold preparatory to the beginning of acontinuous-casting operation;

FIG. 2 is a vertical sectional view taken substantially along the linelI-II of FIG. 1;

FIG. 3 is a top plan view of FIG. 1;

FIG. 4 is an enlarged elevational view, partly in section, showing thebeginning of separation of a starter bar from a continuous-casting inaccordance with the invention; and

FIGS. 5 and 6 are diagrammatic elevational views illustrating the stepsof the operation wherein separation of the starter bar and acontinuously cast casting is effected in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawing, with particular reference to FIGS. I, 3 and 4 for themoment, reference numeral 2 designates a tubular flow-through chill moldused for continuous-casting. Reference numeral 4 designates the headportion of a starter bar 6 which is provided with a cup-shaped recess 8in its upper end having an open end 10 along one lateral edge of thehead portion 4. An inverted T-slot 12 is disposed below and incommunication with the recess 8. The slot 12 extends transversely acrossa major portion of the width of the starter bar 6 to an open end I6which connects with the open end 10 of the recess 8.

A complementary-shaped chill plate 14 having an open bottom 18 isslidably fitted in the recess 8 with its open bottom overlying the upperend of the slot 12.

A key 20, which is substantially in the form of a rail section having ahead 22, a base 24, a web 26, and a flange 28 extending on oppositesides of the web 26 intermediate and parallel with the head 22 of thebase 24, is disposed in the cup-shaped chill plate 14. The flangeportions 28 of the rail section key 20 are undercut and are welded tothe bottom portion of the chill plate 14 closing and sealing its openbottom 18 so that molten metal cannot leak from the chill plate. Thebase 24 of the rail section key is slidably fitted in the head 30 of theinverted T- shaped slot 12. The head 22 of the rail section key 20projects above the bottom of the chill plate and serves as an anchoragefor solidifying metal in the bottom of the mold when continuous-castingis begun as will become apparent hereinafter.

The upper part of the chill plate 14 is provided with an outwardlyprojecting lip 32 which rests on the upper end surface of the headportion of the starter bar and serves to support the chill plate andalso prevent leakage of molten metal into the recess 8. When the starterbar is inserted in the bottom of the mold, a packing 33 ofheat-resistant material, such as asbestos, is placed around the lip 32of the chill plate 14, as best shown in FIG. 1.

In operation, the head portion 4 of the starter bar 6 with the chillplate 18 and rail section key 20 fitted therein, as described above, isinserted in the bottom of the mold 2 and the seal 33 of asbestos orother heat-resistant material is packed between the lip 32 of the chillplate 14 and the inner surface of the mold wall.

Molten metal is then poured into the top of the mold 2 and as this metalreaches the chill plate 14, it starts to solidify and become anchored tothe upper portion 22 of the rail section key 20. After the bottom of thecasting has solidified in the chill plate 14 and is anchored around thehead 22 of the key 20, power-driven pinch rolls 34 cause the starter bar6 to be moved downwardly out of the flow-through mold while attached tothe bottom of the continuous-casting C so that the casting is supportedthrough the pinch rolls by the starter bar. As the leading end of thecasting C descends below the pinch rolls, it travels past a fulcrum roll36 and then past a bending roll 38, which is mounted on the side of thevertical path of the bar and casting opposite the side on which thefulcrum roll is mounted. The bending roll is suitably mounted formovement toward and from the vertical path of the bar and casting. Asthe leading end of the casting C descends below the axis of the bendingroll 34, the bending roll is actuated laterally to the left, as viewedin FIG. 6. At the same time, the leading end of the starter bar enters avertical guide chute (not shown). When the bending roll is thus movedlaterally, it exerts a lateral force in a horizontal plane to deflectthe leading end of the casting C, as best shown in FIG. 6. When thishappens, chill plate 14 and key 20, which are now attached to the solidbottom of the casting C, are moved laterally out of the recess 8 andslot 12 so that the casting is disconnected from the starter bar. Thestarter bar continues to move downwardly into the vertical guide whilethe continuous-casting moves in an arcuate path caused by deflection ofits leading end by the bending roll 38 for entry into a curved rollerguide (not shown).

I claim:

1. A starter bar for continuous-casting disconnectable from an attachedcontinuously formed casting by lateral deflection of the leading end ofthe casting, said starter bar comprising an elongated main body portionhaving a head end, said head end having a substantially cup-shapedrecess therein, said recess having at least one open end along onelateral edge of said head portion, said body portion having atransversely extending slot communicating with and disposed subjacentsaid recess, said slot being substantially in the form of an inverted Tand having at least one open end coincidental with the open end of saidrecess, a complementary chill plate slidably disposed in said recess, akey fixedly attached to said chill plate with one end projectingupwardly therefrom and its other end depending downwardly therefrom andfitting slidably in said slot, said key being substantially in the formof a rail section, said rail section having a base slidably disposed inthe head of said inverted T-slot a web extending slidably upwardly fromsaid base to project above the bottom of said chill plate, and a head onsaid upwardly projecting web. said web being fixedly attached and sealedto said chill plate at a point intermediate said base and said head ofsaid rail section, said head forming an anchorage for the lower end of acontinuously formed casting as it solidifies whereby said key and saidchill plate are disconnected laterally from said starter bar when thelower end of said casting anchored to said key is deflected laterally.

2. In a continuous-casting apparatus including a substantiallyvertically disposed tubular flow-through chill mold for producing acontinuous-casting from molten metal poured in the upper end of saidmold, and means spaced below said mold for laterally deflecting acasting issuing from said mold, the improvement therewith of a starterbar insertable in the lower end of said mold for attachment with thelower end of a casting forming in said mold and disconnectable from saidcasting by lateral deflection of the lower end of the casting, saidstarter bar comprising an elongated main body portion having a head end,said head end having a recess therein extending transversely thereof,said recess having at least one open end along one lateral edge of saidhead portion, said body portion having a transversely extending slotcommunicating with and disposed subjacent said recess, said slot beingsubstantially in the form of an inverted T and having at least one openend coincidental with the open end of said recess, a complementary chillplate slidably disposed in said recess, a key fixedly attached to saidchill plate with one end projecting upwardly therefrom and its other enddepending downwardly therefrom and fitting slidably in said slot, saidkey being substantially in the form of a rail section, said rail sectionhaving a base slidably disposed in the head of said inverted Tslot a webextending slidably upwardly from said base to project above the bottomof said chill plate, and a head on said upwardly projecting web, saidweb being fixedly attached and sealed to said chill plate at a pointintermediate said base and said head of said rail section, said headforming an anchorage for the lower end of a continuously formed castingas it solidifies whereby said key and said chill plate are disconnectedlaterally from said starter bar when the lower end of the castinganchored to said key is deflected laterally by said deflecting means.

1. A starter bar for contInuous-casting disconnectable from an attachedcontinuously formed casting by lateral deflection of the leading end ofthe casting, said starter bar comprising an elongated main body portionhaving a head end, said head end having a substantially cup-shapedrecess therein, said recess having at least one open end along onelateral edge of said head portion, said body portion having atransversely extending slot communicating with and disposed subjacentsaid recess, said slot being substantially in the form of an inverted Tand having at least one open end coincidental with the open end of saidrecess, a complementary chill plate slidably disposed in said recess, akey fixedly attached to said chill plate with one end projectingupwardly therefrom and its other end depending downwardly therefrom andfitting slidably in said slot, said key being substantially in the formof a rail section, said rail section having a base slidably disposed inthe head of said inverted Tslot a web extending slidably upwardly fromsaid base to project above the bottom of said chill plate, and a head onsaid upwardly projecting web, said web being fixedly attached and sealedto said chill plate at a point intermediate said base and said head ofsaid rail section, said head forming an anchorage for the lower end of acontinuously formed casting as it solidifies whereby said key and saidchill plate are disconnected laterally from said starter bar when thelower end of said casting anchored to said key is deflected laterally.2. In a continuous-casting apparatus including a substantiallyvertically disposed tubular flow-through chill mold for producing acontinuous-casting from molten metal poured in the upper end of saidmold, and means spaced below said mold for laterally deflecting acasting issuing from said mold, the improvement therewith of a starterbar insertable in the lower end of said mold for attachment with thelower end of a casting forming in said mold and disconnectable from saidcasting by lateral deflection of the lower end of the casting, saidstarter bar comprising an elongated main body portion having a head end,said head end having a recess therein extending transversely thereof,said recess having at least one open end along one lateral edge of saidhead portion, said body portion having a transversely extending slotcommunicating with and disposed subjacent said recess, said slot beingsubstantially in the form of an inverted T and having at least one openend coincidental with the open end of said recess, a complementary chillplate slidably disposed in said recess, a key fixedly attached to saidchill plate with one end projecting upwardly therefrom and its other enddepending downwardly therefrom and fitting slidably in said slot, saidkey being substantially in the form of a rail section, said rail sectionhaving a base slidably disposed in the head of said inverted T-slot aweb extending slidably upwardly from said base to project above thebottom of said chill plate, and a head on said upwardly projecting web,said web being fixedly attached and sealed to said chill plate at apoint intermediate said base and said head of said rail section, saidhead forming an anchorage for the lower end of a continuously formedcasting as it solidifies whereby said key and said chill plate aredisconnected laterally from said starter bar when the lower end of thecasting anchored to said key is deflected laterally by said deflectingmeans.